Elevating machinery.



A. T. PRESCOTT.

ELEVATING MACHINERY. APPLICATION FILED SEPT. 14,1909.

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. A. T. PRESCOTT. ELEVA'IING MAUHINERY.

APPLICATION FILED SEPL'H, 1909.

. Patented Ju'ne 7, 1910. 1

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ELEVATING MAGHINERY.

APPLIUATIOK FILED SEPT. 14,1909.

960,701 Patented June 7, 1910.

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ANDREW u. GRAHAM cu, wnoro-umocmmzm, WASHKNGTON, u.c.

'A. T. PRESCOTT. ELEVATING MACHINERY. APPLIGATION FILED SEPTL14, 1909.

Patented June 7, 1910.

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ANDREW a GRAHAM cu. FMDTO-UTHOGRAPHERS. WASHUIGTON. \1v 0 t I i EFTQE,

ARTHUR T. PRESCOTT, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 GEORGE E.FROTHINGI-IAM CO., A CORPORATION OF NEW YORK.

ELEVATING MACHINERY.

To all whom it may concern:

Be it known that I, ARTHUR T. Pnnscorr, a citizen of the United Statesof America, and a resident of East Orange, county of Essex, and State ofNew Jersey, have invented certain new and useful Improvements inElevating Machinery, of which the following is a specification,reference being had to the accompanying drawings, forming a partthereof.

My invention relates to elevating machincry, and particularly to meansfor operating transfer bridges of ferry landings and the like.

It is common in this class of transfer bridge operating mechanism toemploy counterweights to carry nearly all of the dead load, and toprovide elevating screws which will carry the live load and theremainder of the dead load. Where these bridges are used in connect-ionwith ferryboats it is common to have the bridge at an elevation slightlyabove the deck of the boat when the boat arrives and to immediatelylower it so that certain parts carried by the bridge rest upon the boat.This relieves the elevating screws of all, or nearly all, of their loadfor the time being, and allows the bridge to move up and down with theboat as it rises and falls with the tide, or as the boat is loaded andunloaded. The bridge is usually pivoted or hinged at its shore end, andthe water end in rising and falling therefore travels in the arc of acircle, and consequently the hanger beam which is near the water end,moves in such an are that the points of suspension will not remain inthe axial lines of the screws. There is also a slight side to sidemovement caused by the movement of the boat and permitted by thelooseness of the side guides of the bridge, and likewise a limitedlongitudinal movement caused by the longitudinal pressure of the vesselas it engages the bridge end. These movements are not great, but theyare suflicient to cause the elevating screws to cramp unless provisionis made to prevent it. In my present invention I provide guides forcausing the screws to travel positively in right lines, and flexibleconnections between the lower ends of the screws and the bridge to'permit the relative movements of the bridge aforementioned. Thisarrangement permits not only free swinging movements of the bridge inevery direction, but permits Specification of Letters Patent.

Application filed September 14, 1909.

Patented June 7, 1910.

Serial No. 517,575.

the screws to be lowered so as to allow the bridge to be supported bythe boat, free of the suspension means.

My invention further consists in providing counterbalancing means forthe screws and parts directly carried thereby, independent of thecounterbalancing means of the bridge, so that the weight of the screwsis taken off the nuts, and the pressure of the nuts upon their bearingsis loosened. These counterbalancing weights are preferably sufficient tooverbalance the screws,that is to say, they are preferably heavier thanthe screws and the directly connected parts, so that the screws areactually lifted thereby when the flexible connections between the screwsand the bridge are slack. This divides the wear between the upper andlower surfaces of the screw and nut threads and also assists in thelubrication of the parts by providing channels for receiving thelubricant.

My invention further consists in an improved construction andarrangement of parts providing for the complete lubrication of theconnecting parts, and particularly of the nut bearings.

My invention also consists in an improved form and construction of thehousings or casings for the nuts, worm wheels, and worms for impartingmovements thereto, permitting the ready removal of the worm from theworm wheel without the necessity of dismantling the whole structure,particularly where a worm and wheel of the Hindley type is employed, asis desirable.

My invention further consists in the employment of means for limitingthe movements of the screws in opposite directions, such meansconveniently comprising electric switches for cutting out the raisingand lowering circuits of the motor employed for imparting movements tothe worm and wheel mechanism in operating the elevating screws.

My invention further consists in many novel details of construction andcombinations of parts, such as will be fully explained hereinafter.

In order that my invention may be clearly understood, I will now proceedto describe an embodiment thereof, having reference to the accompanyingdrawings illustrating the same, and will then point out the novelfeatures in claims.

In the drawings: Figure 1 is a view in front elevation of transferbridge operating machinery constructed in accordance with my invention,showing the same applied to the swinging gangways or bridges of adouble-decked ferry house. Fig. 2 is a view .in central longitudinalsection through the ferryhouse and operating machinery, showing aportion of a ferryboat as contained in the slip and having its decks inline with the transfer bridges. Fig. 3 is a top view of the operatingmechanism. Fig. 1 is a view in central longitudinal section through oneof the elevating screw operating devices. Fig. 5 is a top view of theparts shown in Fig. 4 with the elevating screw in transverse horizontalsection. Fig. 6 is a view in side elevation of the part shown in Fig. 4.Fig. 7 is a transverse sectional view upon the line 7-7 of Fig. 41,showing the guide for the elevating screw.

The ferry landing illustrated is provided with two bridges or gangways,a lower main bridge 10 and an upper gangway 11. The bridge 10 ispivotally supported at its rear end 12 to a stationary part 13 of themain floor of the building, while the gangway 11 is pivoted at its rearend at 14: to an overhead structure 15 constituting an upper floor ofthe building. The elevating mechanism for the lower bridge comprisesvertical non rotatable screws 16 mounted in rotatable nuts 17 supportedby a gallows frame 18, the lower end of each of the screws beingconnected to the forward end of the bridge 10 by means of a rod or wirerope 19 and a section of chain 20. The lower ends of the screws 16 areguided in longitudinal stationary guides 21 by means of slides 22carried by the said screws, the guides 21 being secured to the sidewalls of the ferryhouse or other building by means of frames 23 (seeFigs. 1 and 7). The screws 16 are raised and lowered by the rotation ofthe nuts 17, and the slides 22 and guides 21 in sure the verticalmovement of the said screws in right lines. The flexible connection,however, between the lower ends of the screws and the forward end of thebridge, comprising the links 19 and chains 20, permit the longitudinal,transverse, and swing-- ing movements of the bridge above referred to.Moreover, the chain elements 20, which are allowed to become slack whenthe bridge is supported by the boat, as by its beams 25 resting upon thedeck of the boat, permit the free rising and falling of the bridge withthe boat.

The nuts 17 are provided each with a' worm wheel 26, preferablyremovably secured thereto, so that either the nut or the worm wheel maybe removed and renewed without it being necessary to renew the otherpart, the teeth of the worm wheels being engaged by worms 27 upon a mainoperating shaft 28, the latter being driven by suitable means, as by anelectric motor 29. The worm 27, worm wheel 26, and nut 17 of eachelevated screw are housed within an inclosing casing preferably formedin two parts,- a lower portion 30 and an upper portion 31, the two partsbeing secured together by bolts and nuts 32 which engage flangedportions thereof. The upper end of the upper portion 31 of the casing isprovided with a cuplike flange 33 which constitutes a basin forcontaining lubricating material for the screw, and the upper end of thenut 17 is preferably provided with a steady bearing 31 in the upper partof the portion 31 be neath this oil reservoir; at its lower end the nut17 rests upon a wearing plate 35, being preferably received within ashouldered recess therein. The lower portion 30 of the housing isprovided with a dependent flange 36 and with a sleeve 37 therein, theupper portion of which extends above the level of the bearing plate 35and is received within a suitably recessed portion of the nut 17. Thelower part 30 of the casing may be kept flooded with oil whereby thelower bearing of the nut 17 will be kept thoroughly lubricated. Thelevel of this oil, however, is preferably kept below the level of thetop of the sleeve 36, whereby the oil is prevented from escaping downaround the teeth of the screw 16, as is so common in screw elevatingdevices.

The lower portion of the worm 27 may enter the oil with advantage sothat it will pick up oil and thoroughly lubricate the points of contactbetween the worm and the. worm wheel. The foregoing construction notonly forms a complete housing for the operating parts, such as willthoroughly protect them against injury from external sources, but alsoforms, as will be readily understood, a highly efficient lubricatingmeans for the parts without any waste of the lubricating material beingpermitted. A cover plate 58 may be provided for permitting ready accessto the interior of the casing, for inspection, cleaning, and oilingpurposes.

It will be noted that the two parts 30 and 31 are not divided upon asingle horizontal plane, but, on the contrary, such division is madeupon two planes connected diagonally through the bearing of the shaft28. This is for the purpose of permitting the lateral movement of theshaft 28 and worm 27, after the upper part of the casing is removed andwhile the screw and parts carried thereby are retained in place. Thispermits a worm gearing of the Hindley type to be employed such as canonly be separated by relative lateral movements, while at the same timeit avoids the dividing of the casing throughout on a vertical linethrough the hearing such as would cause the casing to be leaky andincapable of retaining the oil.

It is common in transfer bridges to provide means for counterbalancingthe dead Weight of the bridge, and for this purpose I have shown heavycounterbalancing weights 38 which are connected to the bridge by meansof ropes 39. The ropes 39 pass over direction pulleys 40 carried by thegallows frame 18 and under floating pulleys 41 carried by the bridge 10;the ends of the ropes are anchored to the gallows frame 18 as is shownat 42 in Fig. 2. These weights are usually suflicient to carry almostall of the dead load of the bridge, the live load being carried by theelevating mechanism. The screws 16 and parts directly carried therebyare, however, themselves of considerable weight, running all the wayfrom seven hundred to two thousand pounds, and as this is a dead weightwhich cannot be counterbalanced by the weights 38, or supported by thebridge, I have provided a special counterbalancing means thereforcomprising weights 43 for each screw, connected thereto by wire ropes 44which pass over stationary direction pulleys 45. The weights 43 arepreferably heavy enough to more than counterbalance the screws, so thatthey will tend to press the upper portion of the threads thereof againstthe lower portion of the threads of the nuts, and will also tend to liftthe nuts off their lower bearing surfaces. As the screws normally carrythe remainder of the dead weightof the bridge not carried by thecounterbalancing weights 38 and also carry the live load upon thebridge, these counterbalancing weights will ordinarily be overborne, sothat the normal condition of the screws is with the lower portions ofthe threads in engagement with the upper portion of the threads of thenuts, and with the lower portion of the nuts pressing upon their hearingplates, but when the above mentioned practice is employed of permittingthe bridge to rest upon the boat so that the boat carries the balance ofthe dead weight of the bridge and the live load thereon, and the screwsare lowered to permit freedom of movement, then, for the time being, thescrews will be lifted by their counterbalancing weights 43 in the manneraforesaid, and during the time they are being freely raised and loweredthe wear will be taken off the surfaces which normally take the load andare subjected to the greatest wear, thus saving wear upon thesesurfaces, and further, by reason of the fact that there is always moreor less play, thereby affording channels for the flow of lubricatingmaterial so as to assist in the lubrication of the parts. This latter isquite a valuable feature when it is realized how difficult it is tosueceed in causing oil or grease to flow between surfaces which'are infirm contact.

In order to show a complete operating means for double-decked landings,I have shown a connection with the main shaft 28 for operating the uppergangways 11, but it will be understood that the same forms no part of mypresent invention, but is disclosed and claimed in a copendingapplication filed January 14, 1910, and serially numbered 520,075. Thismeans includes a transverse shaft 46 driven by a worm and wheelconnection 47 with the main shaft 28, and one or more secondary shafts4849 driven by means of worm and worm wheel connections 50 and 51 fromthe said shaft 46. The shafts 4849 are provided with drums 5253 forreceiving chains 5454, the lower ends of which are connected to thegangway The shaft 46 and the shafts 4849 are journaled in suitablebearings in the gallows frame 18.

In order to prevent accidental overthrow movements of the elevatingscrews 16, I have provided cut-out switches 5556 which are arranged tobe operated by a plate 57 carried by the screw 16. Should the screw beraised too high the plate 57 will engage the switch 55 and cut out thecircuit of the electric motor 29 by which movements to raise the screware accomplished, while should the screw descend too far the plate 57will engage the switch 56 to cutout the lowering circuit, wherebyfurther movements in a downward direction will be inhibited.

While I have specially designed the elevating machinery for use inconnection with transfer bridges, and have shown and described it hereinas applied to transfer bridges of ferry houses, it will be understoodthat this is but one application of my invention and that the elevatingmechanism is adapted to a wide range of uses.

What I claim is:

1. In mechanism of the class described, the combination with anelevating screw, means for moving the screw longitudinally, and a guidefor limiting such movements to right line movements, of a swingingconnecting element for connecting the elevating screw with the object tobe raised, whereby the point of connection with the object may movelaterally with respect to the longitudinal movements of the screw.

2. In mechanism of the class described, the combination with a swingingbridge, elevating screws therefor, and means for oper ating theelevating screws, of guides for limiting the movements of the screws toright line movements, and swinging connections bet-ween the bridge andthe elevating screws.

3. In mechanism of the class described, the combination with anelevating screw, means for moving the screw longitudinally, and a guidefor limiting such movements to right line movements, of a flexibleswinging connecting element for connecting the elevating screw with theobject to be raised.

4. In mechanism of the class described,

the combination with an elevating screw, means for moving the screwlongitudinally, and a guide for limiting such movements to right linemovements, of a flexible swinging connecting element for connecting theelevating screw with the object to be raised, the said flexible elementincluding a section of chain.

5. In mechanism of the class described, the combination with a swingingbridge, elevating screws therefor, and means for operating the elevatingscrews, of a guide for limiting such movements to right line movements,and a flexible connection for connecting the bridge with the screws.

6. In mechanism of the class described, the combination with a swingingbridge, elevating screws therefor, and means for operating the elevatingscrews, of a guide for limiting such movements to right line movements,and a flexible chain connection for connecting the bridge with thescrews.

7. In mechanism of the class described, the combination with anelevating screw, and means for suspending a load therefrom, of acounterbalancing weight therefor, in opposition to the weight of thescrew and the load.

8. In mechanism of the class described, the combination with anelevating screw, and means for suspending a load therefrom, of acounterbalancing weight therefor sufficiently heavy to overbalance thescrew and its positively connected parts, in opposition to the weight ofthe screw and the load.

9. In mechanism of the class described, the combination with anelevating screw, a nut thereon, and a lower bearing for the nut, of acounterbalancing weight for the screw and nut sufficiently heavy to liftthe screw, nut and positively connected parts, when the weight of theobject to be lifted is not supported by the said screw.

10. In mechanism of the class described, the combination with a swingingbridge, an elevating screw therefor, and a flexible connection betweenthe elevating screw and the bridge, whereby the weight of the bridge maybe independently borne and the elevating screw feed therefrom, of acounterbalancing weight for the screw of suflicient weight to lift thescrew when thus freed from the weight of the bridge.

11. The combination with a vertical spindle and a rotatable elementthereon provided with a downwardly projecting sleeve spaced from thespindle, of a casing inclosing the said element and provided with asleeve, the upper end of which is received between the first said sleeveand the pinion, the said casing and the sleeve of the said elementhaving coacting bearing surfaces within the said cas ng.

12. The combination with a vertical spindle and a rotatable elementthereon, provided with a downwardly projecting sleeve spaced from thespindle, of an annular oil casing surrounding the said spindle andinclosing the said element, the inner wall thereof being in the form ofan uprising sleeve disposed concentrically with the said spindle, theupper end thereof being received in the space between the first saidsleeve and the spindle, the said casing being provided with a stepbearing below the level of the upper end of the said casing sleeve forengagement with the lower end of the sleeve of the said element.

13. In mechanism of the class described, the combination with anelevating screw, a nut thereon, and a step bearing for the nut, of aninclosing casing having a sleeve therein for surrounding the screw, theupper level of which is above the level of the step bearing, the saidcasing being adapted to contain oil up to the level of the sleeve,whereby the step bearing will be lubricated but the lubricating materialwill be prevented from overflowing around the screw.

lt. In mechanism of the class described, the combination with anelevating screw, a nut thereon, a casing for inclosing the said nut, anda step bearing for the nut within the casing removably secured thereto,of a sleeve connected with the casing, surrounding the screw within thenut, and rising to a point above the step bearing, the said sleeve andcasing constituting an oil receptacle for maintaining the step bearingflooded with oil while preventing the oil from escaping to the threadsof the screw.

15. In mechanism of the class described, the combination with anelevating screw, a

nut thereon, and a step bearing for the nut,

of an inclosing casing for the nut and step bearing, the said casingconstituting an oil chamber for containing oil for flooding the stepbearing, and having a flanged cupshaped portion above the said nut forcontaining lubricating material for the threads of the screw, the saidcasing being open at the bottom to permit the lower end of the screw topass freely through it.

16. In mechanism of the class described, the combination wit-h anelevating screw, a nut thereon, and a step bearing, of an inclosingcasing for the nut and step bearing, the said casing being also providedwith an upper bearing for the said nut and provided with means forindependently lubricating the threads of the screw, the upper bearing,and the said step bearing.

17. In mechanism of the class described, the combination with anelevating screw, a nut thereon, and worm wheel teeth carried by the saidnut, of a worm for engaging the said worm wheel teeth, a casing forinclosing the nut, the worm and the worm wheel, the

shaft of the said Worm being journaled in In Witness whereof, I havehereunto Set the casing, the said casing being divided my hand this 10thday of September5l909. upon two planes transversely connected throughthe bearing of the Worm Wheel ARTHUR PRESCOTT 5 shaft whereby the wormand shaft may be Witnesses:

moved horizontally from the Worm Wheel HORATIO OKEEFE,

When the casing members are moved apart. D. E. DEUTSOH.

